Deucrictibant Demonstrates Durable Efficacy and Safety in Long-Term Prophylaxis of Hereditary Angioedema
Interim results from the open-label extension (OLE) of the CHAPTER-1 phase 2 trial support the long-term efficacy and safety of deucrictibant, an oral bradykinin B2 receptor antagonist, for hereditary angioedema (HAE) prophylaxis, according to an abstract presented at the American College of Allergy, Asthma & Immunology 2025 Annual Scientific Meeting.
The study enrolled 34 participants aged 18 to 75 years with HAE types 1 or 2. Of these, 30 completed part 1 and continued into the OLE, receiving deucrictibant 40 mg daily. At data cutoff (June 10, 2024), the mean treatment duration in the OLE was 12.8 months (maximum 20.8), with up to 23.7 months of total exposure to deucrictibant.
Deucrictibant was well tolerated with no treatment-related serious adverse events. The mean (SD) baseline attack rate was 2.18 (1.35), which decreased to a least squares mean (SE) of 0.15 (0.05) during the OLE. Use of on-demand medication was also infrequent, with a monthly rate of 0.07 (0.02) attacks.
Reductions in attack rates were robust across the cohort. From baseline, 93.1% of participants experienced at least a 50% or 70% reduction in attacks, and 79.3% achieved a ≥90% reduction. Over half (55.2%) were attack-free during the OLE.
“Attack rate in the OLE was low irrespective of participants’ attack rate at study baseline,” the investigators reported. These data indicate consistent benefit across varying baseline severities.
The study authors concluded that “CHAPTER-1 OLE results provide additional evidence on the long-term safety and efficacy of deucrictibant for prophylaxis of HAE attacks.” Final OLE data will be presented in full upon study completion.
Deucrictibant represents a promising oral option for long-term prevention of HAE attacks, with sustained efficacy and minimal reliance on on-demand rescue medication.
Reference
Long-term safety and efficacy of oral deucrictibant for prophylaxis in hereditary angioedema: CHAPTER-1 open-label extension. Presented at: American College of Allergy, Asthma & Immunology 2025 Annual Scientific Meeting; November 6-10, 2025; Orlando, FL.
